Ya for sure mosquito larva, however mosquitos and their larva are delicious snacks for bats and dragonflies. It’s all part of the big picture, I guess. I’ve been thinking about doing a little pond like this. We have a bat box but no bats yet. Of course I don’t want mosquitos but I have seen dragonflies and bats at night so I think nature would balance. We’ll see! I would just be so happy to see a little frog. Little wet man. Wet little boy with a big happy mouth.